Nano-scale light-emitting diode (LED) electrode assembly emitting polarized light, method of manufacturing the same, and polarized LED lamp having the same

ABSTRACT

The present invention relates to a nano-scale light emitting diode (LED) electrode assembly emitting polarized light, a method of manufacturing the same, and a polarized LED lamp having the same, and more particularly, to a nano-scale LED electrode assembly in which partially polarized light close to light that is linearly polarized having one direction is emitted as an emitted light when applying a driving voltage to the nano-scale LED electrode assembly and also nano-scale LED devices are connected to a nano-scale electrode without defects such as an electrical short circuit while maximizing a light extraction efficiency, a method of manufacturing the same, and a polarized LED lamp having the same.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2015-0161292, filed on Nov. 17, 2015, the disclosureof which is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of the Invention

The present invention relates to a nano-scale light emitting diode (LED)electrode assembly emitting polarized light, a method of manufacturingthe same, and a polarized LED lamp having the same, and moreparticularly, to a nano-scale LED electrode assembly that emitspolarized light, in which partially polarized light close to light thatis linearly polarized in one direction is emitted when a driving voltageis applied to the nano-scale LED electrode assembly, while lightextraction efficiency is simultaneously maximized and a nano-scale LEDdevice is connected to a nano-scale electrode assembly without defectssuch as an electrical short circuit, etc. a method of manufacturing thesame, and a polarized LED lamp having the same.

2. Discussion of Related Art

Light emitting diodes (LEDs) have been actively developed, for example,by Nakamura of the Japanese Nichia Co., who succeeded in fusing ahigh-quality single crystal gallium-nitride (GaN) semiconductor byapplying a low-temperature GaN compound buffer layer in 1992. An LED isa semiconductor having a structure in which an n-type semiconductorcrystal in which majority carriers are electrons and a p-typesemiconductor crystal in which majority carriers are holes which come incontact with each other using a characteristic of a compoundsemiconductor, and is a semiconductor device in which an electricalsignal is converted into light having a wavelength band of a desiredregion. Regarding LEDs, Korean Patent Publication No. 2009-0121743discloses a method of manufacturing an LED, and an LED manufacturedaccording thereto.

LED semiconductors have low energy consumption because of their greatlight conversion efficiency, have a semi-permanent lives, and areeco-friendly green devices, and thus have been called revolutionary inthe field of light. Recently, due to developments in compoundsemiconductor technology, high-intensity red, orange, green, blue, andwhite LEDs have been developed, and such LEDs are being applied invarious fields such as traffic lights, mobile phones, automobileheadlights, outdoor billboards, liquid crystal display (LCD) back lightunits (BLUs), interior and exterior lighting, etc., and active studiesare continuously progressing both in Korea and elsewhere. In particular,the gallium nitride (GaN) compound semiconductor having a wide bandgapis a material used for manufacturing LED semiconductors emitting lightin the green, blue, and ultraviolet regions, and many studies thereonare progressing because blue LED devices can be used to manufacturewhite LED devices.

Among this series of studies, studies using nano-scale LED devices inwhich the sizes of the LEDs are manufactured in nano-scale ormicro-scale units are actively progressing, and studies on applyingnano-scale LED devices to lightings, displays, etc. are alsoprogressing. Aspects that have continuously received attention in suchstudies relate to an electrode which is able to apply power to anano-scale LED device, an application purpose, an electrode arrangementfor decreasing a space occupied by an electrode, and a method ofinstalling a nano-scale LED in an arranged electrode, etc.

Among these, the method of installing a nano-scale LED in an arrangedelectrode still has a problem that it is difficult to arrange andinstall a nano-scale device on an electrode as desired due to sizelimitations of nano-scale LED devices. This is because nano-scale LEDdevices cannot be arranged and installed in a desired electrode regionby hand one by one due to the nano-scale or micro-scale sizes ofnano-scale LED devices.

Further, even when a nano-scale LED device is installed in a desiredelectrode region, it is very difficult to control the number ofnano-scale LED devices and the positional relationship between thenano-scale LED devices and the electrode included in a unit electroderegion as desired, and when LED devices are arranged on atwo-dimensional plane, it is difficult to obtain an excellent amount oflight because the number of LED devices included in the unit electroderegion is limited. Further, it is difficult to obtain a desired amountof light because not every LED device connected to two differentelectrodes is able to emit light without defects such as an electricalshort circuit, etc.

In order to solve this problem, the inventor(s) of the present inventiondisclosed a manufacturing method of implementing a nano-scale LED deviceas an electrode assembly by applying power to a nano-scale electrodeline, and a nano-scale LED electrode assembly using the same in KoreanPatent Registration No. 10-1490758, but the nano-scale LED device is notaligned as desired because the electrode assembly is implemented withself-alignment of the nano-scale LED device, and the nano-scale LEDelectrode assembly having irregular device directivity and connected todifferent electrodes is implemented, and thus it is difficult to installthe nano-scale LED at a desired level and it is difficult to obtain thedesired amount of light.

In order to solve this problem, the inventor(s) of the present inventionrecognized that a nano-scale LED electrode assembly emits partiallypolarized light close to light that is linearly polarized in onedirection and also that an intensity of the emitted light is remarkablyincreased when the device is installed on an electrode with constantdirectivity through continued studies for improving alignment when LEDdevices are installed on an electrode, thus completing presentinvention.

SUMMARY OF THE INVENTION

The present invention is directed to providing a nano-scale lightemitting diode (LED) electrode assembly that enables intensity ofemitted light to be improved by increasing alignment of nano-scale LEDdevices installed in a nano-scale electrode line and remarkablyincreasing the number of nano-scale LED devices installed, and thatemits partially polarized light close to light that is linearlypolarized as the emitted light, and a method of manufacturing the same.

Further, the present invention is directed to providing a polarized LEDlamp emitting remarkably excellent polarized light without a polarizerthat transmits only polarized light of a specific direction, through anano-scale LED electrode assembly emitting partially polarized lightclose to light that is linearly polarized in one direction.

According to a first implementation example of the present invention inorder to achieve the first purpose described above, there is provided anano-scale LED electrode assembly emitting polarized light including anelectrode line including a first installation electrode and a secondinstallation electrode which are spaced apart from each other on thesame plane, and a plurality of nano-scale light emitting diode (LED)devices in which one end of the device in a longitudinal direction is incontact with the first installation electrode and the other end is incontact with the second installation electrode, wherein the number ofnano-scale LED devices having an installation angle which is within anangle change range of ±30° from an average installation angle of all ofthe nano-scale LED devices emitting light in the nano-scale LEDelectrode assembly is equal to or more than 80% of the total number ofnano-scale LED devices emitting light, where the installation angle isan acute angle among angles formed by the nano-scale LED device and thefirst installation electrode or the second installation electrodemeasured when the installation angle when the nano-scale LED device isinstalled to be perpendicular to the first installation electrode or thesecond installation electrode is defined as 0°.

According to one implementation example of the present invention, alength of the nano-scale LED device may be 100 nm to 10 μm.

According to another implementation example of the present invention,the nano-scale LED device may include a first conductive semiconductorlayer, an active layer formed on the first conductive semiconductorlayer, and a second conductive semiconductor layer formed on the activelayer, and include an insulating film covering an entire outer surfaceof at least the active layer in order to prevent an electrical shortcircuit generated by contact between the active layer of the nano-scaleLED device and the electrode line.

According to still another implementation example of the presentinvention, an aspect ratio of the nano-scale LED device may be 1.2 to100.

According to another implementation example of the present invention,the number of nano-scale LED devices having an installation angle whichis within the angle change range of ±30° based on the averageinstallation angle may be equal to or more than 90% of the total numberof nano-scale LED devices emitting light.

According to still another implementation example of the presentinvention, the number of nano-scale LED devices having an installationangle which is within the angle change range of ±10° of the averageinstallation angle of all of the nano-scale LED devices emitting lightin the nano-scale LED electrode assembly may be equal to or more than70% of the total number of nano-scale LED devices emitting light.

According to the present invention in order to achieve the first purposedescribed above, there is provided a method of manufacturing anano-scale light emitting diode (LED) electrode assembly emittingpolarized light, including: (1) injecting a solution including aplurality of nano-scale LED devices into an electrode line including abase substrate, a first installation electrode formed on the basesubstrate, and a second installation electrode formed to be spaced apartfrom each other on the same plane as the first installation electrode;and (2) causing the plurality of nano-scale LED devices to self-align byapplying power to the electrode line in order to connect ends of thenano-scale LED devices to the first installation electrode and thesecond installation electrode, wherein the power is alternating currentpower which has a voltage of 10 to 500 V_(pp), and a frequency of 50 kHzto 1 GHz.

According to one implementation example of the present invention, thenano-scale LED device may include a first conductive semiconductorlayer, an active layer formed on the first conductive semiconductorlayer, and a second conductive semiconductor layer formed on the activelayer, and include an insulating film covering an entire outer surfaceof at least the active layer in order to prevent an electrical shortcircuit by contact between the active layer of the nano-scale LED deviceand the electrode line.

According to another implementation example of the present invention, anaspect ratio of the nano-scale LED device may be 1.2 to 100.

According to another implementation example of the present invention,step (1) may include: 1-1) manufacturing the electrode line includingthe base substrate, the first installation electrode formed on the basesubstrate, and the second installation electrode formed to be spacedapart from each other on the same plane as the first installationelectrode; 1-2) forming an insulating barrier surrounding an electrodeline region in which the nano-scale LED devices are installed on thebase substrate; and 1-3) injecting the solution including the pluralityof nano-scale LED devices into the electrode line region surrounded bythe insulating barrier.

According to another implementation example of the present invention,the power may be alternating current power which has a voltage of 35 to250 V_(pp), and a frequency of 90 kHz to 100 MHz.

According to a second implementation example of the present invention inorder to achieve the first purpose described above, there is provided anano-scale LED electrode assembly emitting polarized light including anelectrode line including a first installation electrode and a secondinstallation electrode which are spaced apart from each other on thesame plane, and a plurality of nano-scale LED devices of which one endof the device in a longitudinal direction is in contact with the firstinstallation electrode and the other end is in contact with the secondinstallation electrode, wherein the nano-scale LED electrode assemblyemits polarized light in which a polarization ratio according to thefollowing Equation 1 is equal to or more than 0.25.

$\begin{matrix}{\rho = \frac{I_{\max} - I_{\min}}{I_{\max} + I_{\min}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

In Equation 1, I_(max), and I_(min) are a maximum intensity and aminimum intensity of the light measured while rotating a polarizationaxis of a polarizer from −90° to +90° after placing the polarizer on alight emitting surface of the nano-scale LED electrode assembly.

According to one implementation example of the present invention, thepolarization ratio according to the Equation 1 may be equal to or morethan 0.40.

According to a third implementation example of the present invention inorder to achieve the first purpose described above, there is provided anano-scale LED electrode assembly emitting polarized light including anelectrode line including a first installation electrode and a secondinstallation electrode which are spaced apart from each other on thesame plane, and a plurality of nano-scale LED devices of which one endof the device in a longitudinal direction is in contact with the firstinstallation electrode and the other end is in contact with the secondinstallation electrode, wherein an average installation angle of all ofthe nano-scale LED devices emitting in the nano-scale LED electrodeassembly is equal to or less than 30°, where the installation angle isan acute angle among angles formed by the nano-scale LED device and thefirst installation electrode or the second installation electrodemeasured when the installation angle of a case in which the nano-scaleLED device is installed to be perpendicular to the first installationelectrode or the second installation electrode is defined as 0°.

According to one implementation example of the present invention, theaverage installation angle may be equal to or less than 20°.

According to the present invention in order to achieve the secondpurpose described above, there is provided a polarized light emittingdiode (LED) lamp, including: a supporter; and a nano-scale LED electrodeassembly according to any one of the first implementation example to thethird implementation example of the present invention included insidethe supporter.

According to one implementation example of the present invention, thenano-scale LED electrode assembly may include one among a nano-scale UVLED device, a nano-scale blue LED device, a nano-scale green LED device,a nano-scale yellow LED device, a nano-scale amber LED device, and anano-scale red LED device.

According to another implementation example of the present invention,the supporter may have a cup shape, and further include a fluorescentsubstance included in a cup and excited by light emitted from anano-scale LED electrode assembly.

According to still another implementation example of the presentinvention, the lamp may include a plurality of nano-scale LED electrodeassemblies, and each of the plurality of nano-scale LED electrodeassemblies may independently include one among the nano-scale UV LEDdevice, the nano-scale blue LED device, the nano-scale green LED device,the nano-scale yellow LED device, the nano-scale amber LED device, andthe nano-scale red LED device. In this case, the polarized LED lamp maybe a lamp emitting white light.

According to another implementation example of the present invention,the plurality of nano-scale LED electrode assemblies may be arranged tohave a line arrangement or a plane arrangement.

According to still another implementation example of the presentinvention, when the nano-scale LED electrode assembly includes thenano-scale UV LED device, the fluorescent substance may be any one ormore among blue, yellow, green, amber, and red, and when the nano-scaleLED electrode assembly includes the nano-scale blue LED device, thefluorescent substance may be any one or more among yellow, green, amber,and red.

Here, a term used herein will be described.

“Installation electrode” as used herein may mean an electrode which isin direct contact with both ends of the nano-scale LED device and is nota driving electrode for driving the nano-scale LED electrode assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent to those of ordinary skill in theart by describing exemplary embodiments thereof in detail with referenceto the accompanying drawings, in which:

FIG. 1 is a perspective view and a partially enlarged view of anano-scale light emitting diode (LED) electrode assembly according toone implementation example of the present invention;

FIG. 2 is a perspective view of a nano-scale LED electrode assemblyaccording to a comparison example of the present invention;

FIG. 3 is an optical microscope photograph of a nano-scale LED deviceaccording to a comparison example of the present invention;

FIG. 4 is a planar diagram of a nano-scale electrode assembly accordingto an embodiment of the present invention;

FIG. 5 is a perspective view of a nano-scale LED device included in anembodiment of the present invention;

FIG. 6A is a photograph of light emission in a darkroom when drivingpower is applied to a nano-scale LED electrode assembly according to anembodiment of the present invention, FIG. 6B is an optical microscopephotograph of a nano-scale LED electrode assembly under the sameconditions, and FIG. 6C is a graph illustrating a relative intensity oflight passing through a polarizer according to a polarizer rotationangle;

FIG. 7A is a photograph of light emission in a darkroom when drivingpower is applied to a nano-scale LED electrode assembly according to anembodiment of the present invention, FIG. 7B is an optical microscopephotograph of a nano-scale LED electrode assembly under the sameconditions, and FIG. 7C is a graph illustrating a relative intensity oflight passing through a polarizer according to a polarizer rotationangle;

FIG. 8A is a photograph of light emission in a darkroom when drivingpower is applied to a nano-scale LED electrode assembly according to anembodiment of the present invention, FIG. 8B is an optical microscopephotograph of a nano-scale LED electrode assembly under the sameconditions, and FIG. 8C is a graph illustrating a relative intensity oflight passing through a polarizer according to a polarizer rotationangle of a nano-scale LED electrode assembly according to a comparisonexample of the present invention;

FIG. 9 is a planar diagram illustrating a nano-scale LED electrodeassembly according to an embodiment of the present invention;

FIGS. 10A through 10C are diagrams illustrating a process ofmanufacturing a nano-scale electrode assembly according to an embodimentof the present invention;

FIGS. 11A through 11F are diagrams illustrating a manufacturing processof forming an insulating barrier according to an embodiment of thepresent invention;

FIGS. 12A through 12C are diagrams illustrating a process ofmanufacturing a nano-scale electrode assembly according to oneimplementation example of the present invention;

FIG. 13A is a photograph of light emission in a darkroom when drivingpower is applied to a nano-scale LED electrode assembly according to anembodiment of the present invention, FIG. 13B is an optical microscopephotograph of a nano-scale LED electrode assembly under the sameconditions, and FIG. 13C is a graph illustrating a relative intensity oflight passing through a polarizer according to a polarizer rotationangle;

FIG. 14 is a cross-sectional view and a partially exploded view of apolarized LED lamp according to an embodiment of the present invention;

FIGS. 15 and 16 are perspective views of polarized LED lamps accordingto an embodiment of the present invention; and

FIGS. 17 to 20 are diagrams illustrating measurements of an installationangle of a device in a nano-scale LED electrode assembly according toone implementation example of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, embodiments of the present invention will be described inmore detail with reference to the accompanying drawings.

As described above, technology of installing a nano-scale subminiaturelight emitting diode (LED) device in a subminiature electrode line to beelectrically connected at a desired level was insufficient in aconventional method. In order to solve this problem, the inventor(s) ofthe present invention implemented a nano-scale LED electrode assembly byapplying power to a nano-scale electrode line, but since the electrodeassembly was implemented by self-alignment of the nano-scale LEDdevices, the nano-scale LED device was not aligned as desired, thenano-scale LED electrode assembly which was connected to differentelectrodes with irregular device directivity was implemented, and thusit was difficult to install the nano-scale LED devices in the desirednumber and alignment and to obtain the desired amount of light.

In the present invention, a nano-scale LED electrode assembly emittingpolarized light may include an electrode line including a firstinstallation electrode and a second installation electrode which arespaced apart from each other on the same plane, and a plurality ofnano-scale LED devices in which one end of the device is in contact withthe first installation electrode and the other end of the devices is incontact with the second installation electrode, and the number ofnano-scale LED devices having an installation angle which is within anangle change range of ±30° of an average installation angle of all ofthe nano-scale LED devices emitting light in the nano-scale LED assemblyis equal to or more than 80% of the total number of nano-scale LEDelectrodes emitting light in the nano-scale LED electrode assembly.Accordingly, alignment of the nano-scale LED devices installed in thenano-scale electrode line may be remarkably improved, the number ofnano-scale LED devices installed is remarkably increased, an intensityof emitted light and electrical connectivity may be increased due to theincrease in the number of nano-scale LED devices installed, and theinstalled nano-scale LED devices are connected to the nano-scaleelectrode without defects such as an electrical short circuit, etc., andthus partially polarized light close to linearly polarized light isemitted as the emitted light.

First, a nano-scale LED electrode assembly including the electrode lineincluding the first installation electrode and the second installationelectrode which are spaced apart from each other on the same plane, andthe plurality of nano-scale LED devices in which one end of the deviceis in contact with the first installation electrode and the other end ofthe devices is in contact with the second installation electrode will bedescribed.

Since the nano-scale LED electrode assembly is referenced by KoreanPatent Registration No. 10-1429095, and Korean Patent Application No.2014-0085384 disclosed by the inventor(s) of the present invention, adetailed description regarding a structure, a shape, and a material ofan electrode, and a method of manufacturing an electrode line, etc. willbe omitted, and a configuration of the nano-scale LED electrode assemblyrelated to the present invention will be described in detail.

FIG. 1 is a perspective view and a partially enlarged view of anano-scale light emitting diode (LED) electrode assembly according toone implementation example of the present invention, and the nano-scaleLED electrode assembly may include an electrode line including a firstinstallation electrode 110 and 111 formed on a base substrate 400 and asecond installation electrode 130 and 131 formed to be spaced apart fromthe first installation electrode 110 and 111 on the same plane, and aplurality of nano-scale LED devices 120 which are simultaneouslyconnected to the first and second installation electrodes. In detail,one end of one device 121 in a longitudinal direction among theplurality of nano-scale LED devices may be in contact with the firstinstallation electrode 112, and the other end may be electricallyconnected by being in contact with the second installation electrode132.

In the nano-scale LED electrode assembly shown in FIG. 1, the nano-scaleLED devices may be connected to the electrodes by lying prostratebetween the first installation electrode 111 and the second installationelectrode 131 placed on the same plane, and because the nano-scale LEDdevices need not necessarily be connected to be perpendicular to theelectrode, the nano-scale LED devices and the electrode do not need tobe connected three-dimensionally to be perpendicular, and electricalconnectivity may be improved. Further, the nano-scale LED devices may beformed horizontally because the electrodes are formed to be spaced apartfrom each other on the same plane, and thus light extraction efficiencyof the nano-scale LED device may be remarkably improved.

Meanwhile, it is next to impossible for a person or a machine tomanufacture the nano-scale LED electrode assembly shown in FIG. 1 byinstalling the nano-scale LED devices separated into units one by onebecause the sizes of the nano-scale LED devices such as the widths ofthe electrodes and the distance between the electrodes are on amicro-scale or nano-scale. The inventor(s) of the present inventionmanufactured the nano-scale LED electrode assembly shown in FIG. 1 usinga method in which the nano-scale LED devices were self-aligned andconnected to two different installation electrodes by applying powerafter dropping a solution including the nano-scale LED devices on anano-scale electrode line, but was quite difficult to align thenano-scale LED devices at a desired level.

In detail, FIG. 2 is a perspective view of a nano-scale LED electrodeassembly according to a comparison example of the present invention, andillustrates a nano-scale LED electrode assembly in which a plurality ofnano-scale LED devices 221, 222, 223, and 224 are connected to anelectrode line including a first installation electrode 211 and a secondinstallation electrode 212 formed to be spaced apart from each other onthe same plane.

In the nano-scale LED electrode assembly shown in FIG. 2, examiningalignment of the nano-scale LED devices, some of the nano-scale LEDdevices 221, 222, and 224 may be connected on upper surfaces of the twodifferent installation electrodes, and some of the nano-scale LED device223 may be connected between sides of the two different installationelectrodes, and in this case, examining the alignment of the pluralityof nano-scale LED devices 221, 222, 223, and 224, some of the nano-scaleLED devices 221 and 222 may be uniformly aligned so that longitudinaldirections of the installation electrode and the device areperpendicular to each other, but alignment of the plurality ofnano-scale LED devices installed on the electrode line may be irregularsince the nano-scale LED devices 223 are obliquely connected between thesides of the installation electrodes and the nano-scale LED devices 224are obliquely connected on an upper surface of the installationelectrode in another direction,

As described above, since the nano-scale devices are substantiallynano-scale, the nano-scale LED devices cannot be installed precisely ina desired position and in a desired direction on the electrode line oneby one by a machine or the hand of a person, and it is difficult touniformly install all of the nano-scale LED devices to have directivityeven using the conventional method disclosed by the inventor(s) of thepresent invention. In detail, in the method disclosed by the inventor(s)of the present invention, the nano-scale LED devices may be self-alignedon the electrode according to a device surface polarizing phenomenon andan electrostatic force between the electrode and the polarized deviceunder an effect of an electric field, and in this case, it is quitedifficult to uniformly install all of the nano-scale LED devices to havedirectivity since a device movement disposition is influenced by wherethe nano-scale LED devices are located on the two different electrodesbefore the electric field is formed, and how the nano-scale LED devicesare aligned.

In detail, FIG. 3 illustrates an optical microscope photograph ofnano-scale LED devices according to a comparison example of the presentinvention, and because some of the nano-scale LED devices 225, 226, and227 are obliquely connected to the two different installationelectrodes, although the nano-scale LED devices are able to be installedon the nano-scale electrode lines, aligning all of the nano-scale LEDdevices to have any disposition or aligning all of the nano-scale LEDdevices to be vertically installed on the electrode is another problem.

Accordingly, the inventor(s) of the present invention recognized that,when the nano-scale devices are self-aligned based on a specificcondition according to the present invention, the nano-scale LED deviceshave remarkably excellent directivity and alignment, are simultaneouslyconnected to the two installation electrodes without an electrical shortcircuit, emit light having further improved intensity, and also emitpartially polarized light close to light which is linearly polarized inany one direction through continued studies on improving the alignmentof the devices, thus completing the present invention.

First, according to a first implementation example of the presentinvention, the number of nano-scale LED devices having an installationangle which is within an angle change range of ±30° of an averageinstallation angle of all of the nano-scale LED devices emitting lightin the nano-scale LED electrode assembly may be 80% or more, preferably90% or more, of the total number of nano-scale LED devices emittinglight.

Further, according to an embodiment of the present invention, the numberof nano-scale LED devices having an installation angle which is withinan angle change range of ±10° of an average installation angle of all ofthe nano-scale LED devices emitting light in the nano-scale LEDelectrode assembly may be 70% or more, preferably 80% or more, of thetotal number of nano-scale LED devices, and thus the nano-scale LEDdevices may emit light that is linearly polarized closer to a specificdirection, and the intensity of the light emitted by the number ofnano-scale LED devices installed may be further increased.

First, the installation angle may be a parameter determining howobliquely the installed nano-scale LED devices are installed withrespect to the first installation electrode or the second installationelectrode when the nano-scale LED devices are installed to beperpendicular to the first installation electrode and the secondinstallation, and may be an acute angle among angles between alongitudinal axis of the nano-scale LED devices and the firstinstallation electrode or the second installation electrode measuredwhen the installation angle of a case in which the nano-scale LED deviceis installed to be perpendicular to the installation electrode isdefined as 0°. In this case, the nano-scale LED devices which are ameasurement target of installation angle may be the nano-scale LEDdevices actually emitting light when a driving voltage is applied to thenano-scale LED devices, and are not the nano-scale LED devices which aresimply included in the nano-scale LED electrode assembly regardless ofwhether the nano-scale LED devices emit light.

Referring to FIG. 4, when the driving power is applied to all of theplurality of nano-scale LED devices 21, 22, 23, 24, and 25 in which bothends of the devices are connected on the first installation electrodes11 and 13 and the second installation electrodes 12 and 14 and all ofthe plurality of nano-scale LED devices 21, 22, 23, 24, and 25 emitlight, in this case, the installation angle of a first nano-scale LEDdevice 21 may be an acute angle θ₁ among angles between a longitudinaldirection a of the first nano-scale LED device and the firstinstallation electrode 13. Further, the average installation angle maybe an average value of the installation angles of all of thelight-emitting nano-scale LED devices 21, 22, 23, 24, and 25. In thiscase, the angle included in the angle change range of ±30° of theaverage installation angle may be the average installation angle −30° tothe average installation angle +30°.

In this case, according to the first implementation example of thepresent invention, the fact that the number of nano-scale LED deviceshaving the installation angle which is within the angle change range isequal to or more than 80% of the total number of nano-scale LED devicesmay mean that a tendency for a longitudinal direction of the nano-scaleLED devices installed in the installation electrode to be aligned in anyone direction is great.

Referring to FIG. 4, assuming that the installation angles 81, θ₂, θ₃,θ₄, and θ₅ of the plurality of nano-scale LED devices 21, 22, 23, 24,and 25, are 15°, 30°, 32°, 27°, and 65°, respectively, the averageinstallation angle is 33.8°, the angle change range of ±30° of theaverage installation angle is 3.8° to 63.8°, and accordingly, the numberof nano-scale LED devices having the installation angle which is withinthe angle change range among the five nano-scale LED devices 21, 22, 23,24, and 25 is 4, and thus it can be said that 80% of all of thelight-emitting nano-scale LED devices have the installation angleincluded in the angle change range.

When the nano-scale LED assembly is driven, the alignment of thelongitudinal direction of the nano-scale LED devices may need to beimproved in order to emit light close to partially polarized light whichis linearly polarized in any one direction, and in detail, thenano-scale LED devices which are directly connected to the twoinstallation electrodes formed to be spaced apart from each other on thesame plane may be horizontally connected so that sides of the devices(an outer surface which is parallel to the longitudinal axes of thedevices) is parallel to the same plane, light emitted from any onenano-scale LED device which is horizontally connected when the drivingvoltage is applied to the electrode line may have a linearly polarizedlight characteristic of any specific direction due to a differencebetween first light directly escaping from the device by being emittedfrom a multiple quantization well (MQW) of the device and second lightescaping from both ends of the device. However, the direction of thepolarized light may be dependent on a direction in which the nano-scaleLED devices are aligned, and the nano-scale LED devices in which thelongitudinal directions are substantially matched among the nano-scaleLED devices installed on the electrodes may all emit the linearlypolarized light in the same one direction. Accordingly, the nano-scaleLED electrode assembly may emit the partially polarized light close tothe light that is linearly polarized in any specific direction becausethe nano-scale LED devices are aligned and installed on the installationelectrode so that the longitudinal directions of the nano-scale LEDdevices are matched substantially, and may emit the light that islinearly polarized in any one direction when the longitudinal directionsof all of the nano-scale LED device are aligned and installed tosubstantially match.

Accordingly, preferably, as the number of nano-scale LED devices havingthe installation angle which is within the angle change range of ±30° ofthe average installation angle is increased, the nano-scale LEDelectrode assembly may emit the polarized light close to the light thatis linearly polarized in any one direction, and in another preferableaspect, a width of the angle change based on the average installationangle may be a range smaller than ±30°, preferably ±20° or less, andmore preferably ±10° or less, and as the number of nano-scale LEDdevices having the installation angle which is within the angle changewidth is increased, the nano-scale electrode assembly may emit thepolarized light close to the light that is linearly polarized in any onedirection.

When the nano-scale LED devices included in an embodiment of the presentinvention are the nano-scale LED devices which are generally and widelyapplied to lamps, displays, etc., the devices may be used withoutlimitation, and preferably, lengths of the nano-scale LED devices may be100 nm to 10 μm, more preferably 500 nm to 5 μm. When the lengths of thenano-scale LED devices are less than 100 nm, it may be difficult tomanufacture a high-efficiency LED device, and when the lengths of thenano-scale LED devices are more than 10 μm, light emitting efficiency ofthe LED device may be decreased. Shapes of the nano-scale LED devicesmay be various shapes such as cylindrical shapes or rectangular shapes,and are preferably cylindrical shapes but are not limited thereto.Further, an aspect ratio of the nano-scale LED devices may be 1.2 to100, preferably 1.2 to 50, more preferably 1.5 to 20, and mostpreferably 1.5 to 10. When the aspect ratio of the nano-scale LEDdevices is less than 1.2, the nano-scale LED devices may not beself-aligned even when the power is applied to the electrode line, andwhen the aspect ratio of the nano-scale LED devices is more than 100,although a voltage of the power needed for self-alignment may bedecreased, when the nano-scale LED devices are manufactured using dryetching, etc., it may be difficult to manufacture the devices in whichthe aspect ratio is more than 100 due to limitations of the process.

Hereinafter, in a description of the nano-scale LED device, “up, “down”,“top”, “bottom”, “upper”, and “lower” may refer to the verticaldirections up and down based on each layer included in the nano-scaleLED devices.

The nano-scale LED devices may include a first conductive semiconductorlayer, an active layer formed on the first conductive semiconductorlayer, and a second conductive semiconductor layer formed on the activelayer.

In detail, FIG. 5 is a perspective view of a nano-scale LED deviceincluded in one implementation example of the present invention, thenano-scale LED device may include an active layer 120 c formed on afirst conductive semiconductor layer 120 b and a second conductivesemiconductor layer 120 d formed on the active layer 120 c, may furtherinclude a first electrode layer 120 a formed on a lower surface of thefirst conductive semiconductor layer 120 b, and may further include asecond electrode layer 102 e formed on an upper surface of the secondconductive semiconductor layer 120 d.

First, the first electrode layer 120 a will be described.

For the first electrode layer 120 a, a metal or metal oxide used as anelectrode of a conventional LED device, preferably chromium (Cr),titanium (Ti), aluminum (Al), gold (Au), nickel (Ni), indium-tin-oxide(ITO), their oxide, their alloy, etc., may be used alone or incombination, but the present invention is not limited thereto.Preferably, a thickness of the first electrode layer may be 1 to 100 nm,but is not limited thereto. When the first electrode layer is included,the first electrode layer may be bonded at a temperature lower than thatneeded in a process of forming a metal ohmic layer in a connectionportion of the first semiconductor layer and the electrode assembly.

Next, the first conductive semiconductor layer 120 b formed on the firstelectrode layer 120 a will be described. For example, the firstconductive semiconductor layer 120 b may include an n-type semiconductorlayer. When the nano-scale LED device is a blue LED device, the n-typesemiconductor layer may be selected from semiconductor materials havingthe empirical formula In_(x)Al_(y)Ga_(1-x-y)N (0<x<1, 0<y<1, 0<x+y<1),for example, one or more of indium-aluminum-gallium-nitrogen (InAlGaN),gallium-nitrogen (GaN), aluminum-gallium-nitrogen (AlGaN),indium-gallium-nitrogen (InGaN), aluminum-nitrogen (AlN),indium-nitrogen (InN), etc., and may be doped with a first conductivedopant (for example, silicon (Si), germanium (Ge), tin (Sn), etc.).Preferably, a thickness of the first conductive semiconductor layer 120b may be 500 nm to 5 μm, but is not limited thereto. Since a color ofthe light of the nano-scale LED device is not limited to blue, otherkinds of semiconductor materials included in Groups III to V may be usedin the n-type semiconductor layer when the emitted color is different.

Next, the active layer 120 c formed on the first conductivesemiconductor layer 120 b will be described. When the nano-scale LEDdevice is a blue LED device, the active layer 120 c may be formed on thefirst conductive semiconductor layer 120 b, and may be formed to have asingle or multiple quantum well structure. A clad layer (not shown)doped with a conductive dopant may be formed above and/or below theactive layer 120 c, and may be implemented as an AlGaN layer or anInAlGaN layer. In addition, a material such as AlGaN, AlInGaN, etc. maybe used as the active layer 120 c. When an electric field is applied,light may be generated by a recombination of electron-hole pairs in theactive layer 120 c. Preferably, a thickness of the active layer may be10 to 200 nm, but is not limited thereto. The active layer may be formedto be diversely located according to a type of the LED device. Since acolor of the light of the nano-scale LED device is not limited to blue,other types of semiconductor materials included in Groups III to V maybe used for the active layer when the emitted color is different.

Next, the second conductive semiconductor layer 120 d formed on theactive layer 120 c will be described. When the nano-scale LED device isa blue LED device, a second conductive semiconductor layer 102 d may beformed on the active layer 120 c, and be implemented by at least onep-type semiconductor layer, and the p-type semiconductor layer may beselected from a semiconductor material having an empirical formulaIn_(x)Al_(y)Ga_(1-x-y)N (0<x<1, 0<y<1, 0<x+y<1), for example, one ormore of InAlGaN, GaN, AlGaN, InGaN, AlN, InN, etc., and a secondconductive dopant (for example, magnesium (Mg), etc.) may be doped.Here, a light emitting structure may include the first conductivesemiconductor layer 120 b, the active layer 120 c, and the secondconductive semiconductor layer 102 d as a final element, and furtherinclude another fluorescent substance layer, another active layer,another semiconductor layer, and/or another electrode layer on/beloweach layer. Preferably, a thickness of the second conductivesemiconductor layer 120 d may be 50 nm to 500 nm, but is not limitedthereto. Since a color of the light of the nano-scale LED device is notlimited to blue, semiconductor materials included in Groups III to V ofother kinds may be used as the p-type semiconductor layer when theemitting color is different.

Next, the second electrode layer 120 e formed on the second conductivesemiconductor layer 102 d will be described.

The second electrode layer 120 e may use metal or metal oxide used as anelectrode of a conventional LED device, desirably Cr, Ti, Al, Au, Ni,ITO, their oxide, their alloy, etc., alone or in combination, but is notlimited thereto. Preferably, a thickness of the second electrode layermay be 1 nm to 100 nm, but is not limited thereto. When including thesecond electrode layer, the second electrode layer may be bonded using atemperature smaller than that needed in a process of forming a metalohmic layer in a connection portion of the first semiconductor layer andthe electrode assembly.

Meanwhile, the nano-scale LED device included in the nano-scale LEDelectrode assembly according to the present invention may include acoated insulating film 120 f covering an outer surface including theactive layer 120 c of the nano-scale LED device in order to prevent ashort circuit generated by contact between the active layer 120 c of thenano-scale LED device and the electrode line.

In detail, in FIG. 13, the insulating film 120 f may be coated on theactive layer 120 c and the outer surface of the nano-scale LED device,and preferably, the insulating film 120 f may be coated on one or moreof the first conductive semiconductor layer 120 b and the secondconductive semiconductor layer 120 d in order to prevent a decline indurability of the nano-scale LED device due to damage of the outersurface of the semiconductor layer.

The insulating film 120 f may perform a function of preventing theelectrical short circuit generated by the contact of the active layer120 c included in the nano-scale LED device and the electrode. Further,the insulating film 120 f may prevent the defect of the surface of theactive layer 120 c by protecting the outer surface including the activelayer of the nano-scale LED device, and prevent a decline in the lightemitting efficiency.

When each of the nano-scale LED devices is arranged and connected one byone between two different electrodes, the electrical short circuitgenerated by the contact of the active layer and the electrode may beprevented, but it may be difficult to substantially install thenano-scale LED devices in the electrode one by one. Accordingly, whencausing the nano-scale LED devices to self-align between the twodifferent electrodes by applying the power like the present invention,the nano-scale LED devices may perform a position change such asmovement, alignment between the two different electrodes, and in thiscase, the active layer 120 d of the nano-scale LED device may be incontact with the electrode assembly, and thus the electrical shortcircuit may be frequently generated.

Meanwhile, when implementing the electrode assembly by standing thenano-scale LED device on the electrode to be perpendicular to theelectrode, the electrical short circuit generated by the contact of theactive layer and the electrode assembly may not be generated. That is,the active layer and the electrode assembly may be in contact with eachother only when the nano-scale LED device is not stood on the electrodeand is lay down on the electrode, in this case, there may be a problemin which the nano-scale LED device is not connected to the two differentelectrodes, but the problem of the electrical short circuit may not begenerated.

However, since the two different electrodes are formed to be spacedapart from each other on the same plane and the nano-scale LED device isconnected to be lay down in parallel with the same plane on which thetwo electrodes are formed, the problem of the electrical short circuitby the contact of the active layer of the electrode of the nano-scaleLED device which is not generated in the conventional art may benecessarily generated. Accordingly, in order to prevent the problem, theinsulating film covering the entire outer surface of at least the activelayer of the outer surface of the nano-scale LED device may be needed.

Further, like the nano-scale LED device included in the electrodeassembly according to the present invention, the active layer may benecessarily exposed outside in the nano-scale LED device having astructure in which the first semiconductor layer, the active layer, thesecond semiconductor layer are sequentially and vertically arranged.Moreover, in the LED device having the structure, since the active layeris not located only in the center in a longitudinal direction of thedevice and is formed to be located to lean towards the semiconductorlayer, a possibility in which the electrode and the active layer are incontact with each other may be further increased. Accordingly, in orderto achieve the purpose of the present invention, the insulating film maybe needed for allowing the device to be electrically connected to thetwo different electrodes regardless of the position of the active layerin the device.

Desirably, the insulating film (120 f of FIG. 5) may include one or moreof silicon nitride (Si₃N₄), aluminum oxide (Al₂O₃), hafnium oxide(HfO₂), yttrium oxide (Y₂O₃), titanium dioxide (TiO₂), and morepreferably, consist of the ingredients or be transparent, but is notlimited thereto. When the insulating film is transparent, the insulatingfilm may perform the function of the insulating film (120 f of FIG. 5),and also the decrease of the light emitting efficiency which may begenerated by coating the insulating film may be minimized.

Meanwhile, according to one implementation example of the presentinvention, the insulating film (120 f of FIG. 5) may not be coated onone or more of the first electrode layer (120 a of FIG. 5) and thesecond electrode layer (120 e of FIG. 5) of the nano-scale LED device,and more preferably, the insulating film may not be coated on the twoelectrodes layer 120 a and 120 e. The two electrode layers 120 a and 120e and different electrodes should be electrically connected, but whenthe insulating film 120 f is coated on the two electrode layers 120 aand 120 e there may be a problem in which the light emission of thenano-scale LED is decreased or is not generated by the electricaldisconnection since the electrical connection is obstructed. However,when there is the electrical connection between the two electrode layersof the nano-scale LED device 120 a and 120 e and the differentelectrodes, the insulating film 120 f may be included in portions ofremaining electrode layers excluding end portions of the two electrodelayers 120 a and 120 e of the two nano-scale LED devices since there isno problem in the light emission of the nano-scale LED device.

According to one implementation example of the present invention, thenano-scale LED device may further include a hydrophobic film (120 g ofFIG. 5) on the insulating film (120 f of FIG. 5). The hydrophobic film120 g may perform a function of preventing an agglomeration phenomenonbetween the LED devices by allowing a surface of the nano-scale LEDdevice to have a hydrophobic characteristic, remove a problem ofhindering the characteristic of an independent nano-scale device byminimizing agglomeration between the nano-scale devices when thenano-scale LED devices are mixed in a solvent, and each of thenano-scale LED device may be easily aligned more when applying the powerto the electrode assembly.

The hydrophobic film (120 g of FIG. 5) may be formed on the insulatingfilm (120 f of FIG. 5). In this case, some hydrophobic films capable ofpreventing the agglomeration phenomenon between the nano-scale devicesby being formed on the insulating film may be used without limitations,and preferably, self-assembled monolayers (SAMs) such asoctadecyltrichlorosilane (OTS), fluoroalkyltrichlorosilane,perfluoroalkyltriethoxysilane, etc., and pluoropolymers such as teflon,cytop, etc., alone or in combination, may be used for the hydrophobicfilm, but the hydrophobic film is not limited thereto.

Meanwhile, according to a second implementation example according to thepresent invention, in a nano-scale LED electrode assembly including anelectrode line including a first installation electrode and a secondinstallation electrode which are spaced apart from each other on thesame plane, and a plurality of nano-scale LED devices in which one endof the device in a longitudinal direction is in contact with the firstinstallation electrode and the other end of the device is in contactwith the second installation electrode, the nano-scale LED electrodeassembly may emit light in which a polarization ratio according to thefollowing Equation 1 is 0.25 or more.

$\begin{matrix}{\rho = \frac{I_{\max} - I_{\min}}{I_{\max} + I_{\min}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

In Equation 1, I_(max), and I_(min) represent a maximum intensity and aminimum intensity of the light measured while rotating a polarizationaxis of a polarizer from −90° to +90° after installing the polarizer ona light emitting surface of the nano-scale electrode assembly.

As described above, the nano-scale LED electrode assembly according tothe present invention may emit the partially polarized light close tothe linearly polarized light having any one direction since the devicesinstalled on the electrode are substantially connected in parallel inthe longitudinal direction, and more preferably, be connected on theelectrode so that the longitudinal direction is perpendicular to theelectrode. Accordingly, the polarization ratio by Equation 1 may be 0.25or more, more preferably 0.40 or more, and much more preferably 0.54 ormore.

When describing the polarization ratio by Equation 1 in detail, thepolarization ratio may mean a ratio related to the maximum intensity andthe minimum intensity of the light measured while rotating thepolarization axis of the polarizer within −90°˜+90° after positioningthe polarizer on an upper surface of the nano-scale LED electrodeassembly, and when the polarization ratio is 1, I_(min) means 0, and thelight emitted from the nano-scale electrode assembly may mean the lightwhich is completely and linearly polarized in a specific direction. Whenthe polarization ratio is 0, the light emitted from the nano-scale LEDelectrode assembly may mean that the light having the same intensity isemitted regardless of an angle formed by the nano-scale LED device andthe polarization axis of the polarizer since the light emitted from thenano-scale LED electrode assembly is not polarized.

The nano-scale LED electrode assembly according to the present inventionmay emit the polarized light further close to light that is linearlypolarized since the alignment of the devices is very excellent, and thenano-scale LED electrode assembly according to the present inventionhaving the very excellent alignment may greatly be suitable for variousapplications required to emit the polarized light since emitting thelight in which the polarization ratio is 0.25 or more without includinga separate polarizer may be recognized as emitting the light having anexcellent polarization ratio in this art.

In detail, FIGS. 6C, 7C, 8C, and 13C are results obtained by measuring apolarizer degree of the light emitted from the nano-scale LED electrodeassembly according to various implementation examples of the presentinvention, it may be known that the intensity of the emitted light isgreat when an angle formed by the nano-scale LED device and thepolarization axis of the polarizer is close to 0° in the nano-scale LEDelectrode assemblies shown in FIGS. 6C, 7C, 8C, and 13C, and theintensity of the emitted light is small as the angle is changed from 0to ±90°. Through the results, it may be clearly confirmed that thenano-scale LED electrode assemblies shown in FIGS. 6C, 7C, 8C, and 13Cemit the polarized light when applying the driving power, and in detail,emit the light in which the polarized light is excellent as thepolarization ratio of the nano-scale LED electrode assembly shown inFIG. 6C is 0.61, the polarization ratio of the nano-scale LED electrodeassembly shown in FIG. 7C is 0.60, the polarization ratio of thenano-scale LED electrode assembly shown in FIG. 8C is 0.45, and thepolarization ratio of the nano-scale LED electrode assembly shown inFIG. 13C is 0.45.

Meanwhile, the nano-scale LED electrode assembly according to a thirdimplementation example according to the present invention satisfies thatthe average installation angle of all of the nano-scale LED devicesemitting in the nano-scale LED electrode assembly when applying thedriving power is 30° or less, preferably 20° or less, more preferably10° or less, much more preferably 5° or less.

In this case, since the average installation angle has the same meaningas the average installation angle in the first implementation exampledescribed above, and a description regarding the method of calculatingthe average installation angle will be omitted.

More preferably, the installation angle of each of the nano-scale LEDdevice may be close to 0°, in this case, the nano-scale LED devicesinstalled in the nano-scale LED electrode assembly may be most denselyinstalled in the electrode line, and the light emitted from thenano-scale LED device may be the linearly polarized light having any onedirection since the alignment of the devices is very excellent. When theaverage installation angle of the emitting nano-scale LED devices ismore than 30°, the number of devices installed in a unit area of theinstallation electrode line may be remarkably decreased since thealignment on the installation electrode of the devices is not good,polarization directions of the light emitted from the devices aredifferent from each other when applying the driving voltage to thenano-scale LED electrode assembly, and thus the nano-scale LED devicemay be difficult to emit the partially polarized light close to thelinearly polarized light having any one direction.

Referring to FIG. 9, when an angle formed by a longitudinal axisdirection a₁ of a sixth nano-scale LED device 26 and a firstinstallation electrode 17 is 90°, and an angle formed by thelongitudinal axis direction b₁ of a seventh nano-scale LED device 27 andthe first installation electrode 17 is 90°, and the number of nano-scaleLED devices installed in a limited region B may be remarkably increasedas being confirmed from the portion B in FIG. 9 when the installationelectrode and the longitudinal direction of the device are installed tobe vertical or close to verticality like the sixth nano-scale LED device26 and the seventh nano-scale LED device 27. That is, at least two ormore nano-scale LED devices 28 and 29 may be installed in a regionoccupied by a tenth nano-scale LED device 30 obliquely connected to thefirst installation electrode 15 and the second installation electrode16, and through this, when the nano-scale LED device is installed sothat the electrode and the longitudinal direction of the device arevertical, a region in which the nano-scale LED device is able to beinstalled is increased, the number of devices which is actuallyinstalled is increased, the amount of emitted light is increased, andthus the emitted light may be the linearly polarized light having anyone direction.

Further, when the installation electrode and the longitudinal directionof the device are connected to close to the verticality, a contact areabetween the end portion of the device and the installation electrode maybe increased, and thus the electrical connectivity may be increased.Since an edge c of one end of the device is slightly connected over theinstallation electrode 16, a tenth nano-scale LED device 30 shown inFIG. 9 may be easily disconnected, and thus the electrical defect may begenerated.

Hereinafter, a method of manufacturing the nano-scale LED electrodeassemblies according to the first to third implementation examples ofthe present invention will be described. The present invention is notlimited to the method which will be described hereinafter.

The nano-scale LED electrode assembly according to one implementationexample of the present invention may manufacture the nano-scale LEDelectrode assembly including (1) injecting solution including aplurality of nano-scale LED devices into a base substrate, and anelectrode line including a first installation electrode formed on thebase substrate and a second installation electrode formed to be spacedapart from each other on the same plane as the first installationelectrode, and (2) causing the plurality of nano-scale LED devices toself-align by applying power to the electrode line in order to connectend portions of the nano-scale LED devices to the first installationelectrode and the second installation electrode, respectively, and thepower may be alternating current power which has a voltage of 10 to 500V_(pp) and a frequency of 50 kHz to 1 GHz.

First, as the operation (1) according to the present invention, (1) theinjecting of the solution including the plurality of nano-scale LEDdevices into the base substrate, and the electrode line including thefirst installation electrode formed on the base substrate and the secondinstallation electrode formed to be spaced apart from each other on thesame plane as the first installation electrode will be described.

In detail, FIGS. 10A through 10C are diagrams illustrating a process ofmanufacturing a nano-scale electrode assembly according to oneimplementation example of the present invention, FIG. 10A illustrates afirst installation electrode 110 formed on a base substrate 100, asecond installation electrode 130 formed to be spaced apart from eachother on the same plane as the first installation electrode, and asolution (an LED device 120, a solvent 140) in which the plurality ofnano-scale LED devices are included.

Since a description regarding detailed manufacturing method andstructure of the electrode line including the base substrate, the firstinstallation electrode, and the second installation electrode isreferenced by Korean Patent Registration No. 10-1429095, and KoreanPatent Application No. 2014-0085384, the manufacturing method will bemainly described in detail hereinafter.

First, the solution 120 and 140 including the plurality of nano-scaleLED devices will be described.

The solution 120 and 140 including the nano-scale LED devices may bemanufactured by mixing the plurality of nano-scale LED devices 120 andthe solution 140. The solution may be ink, or a paste. Preferably, thesolution 140 may be any one selected from a group consisting of acetone,water, alcohol, toluene, more desirable acetone. A kind of the solution140 is not limited thereto, and any solution capable of well evaporatingwithout having a physical or chemical effect on the nano-scale LEDdevice 120 will be used without limitations.

Preferably, the nano-scale LED devices may be included at a content of0.001 to 100 parts by weight, based on 100 parts by weight of thedispersion solvent. When the nano-scale LED devices are included at acontent of less than 0.001 parts by weight, the number of the nano-scaleLED devices connected to the electrodes may be reduced, which makes itdifficult to exert normal functions of the nano-scale LED electrodeassembly. To solve the problems, the dispersion solution may be addeddropwise several times. When the content of the nano-scale LED devicesis greater than 100 parts by weight, an arrangement between theplurality of nano-scale LED devices may be disturbed.

Meanwhile, the operation (1) according to the present invention which isthe injecting of the solution including the nano-scale LED devices intothe electrode line including the first installation electrode and thesecond installation electrode may include 1-1) manufacturing anelectrode line including a base substrate, a first installationelectrode formed on the base substrate, and a second installationelectrode formed to be spaced apart from each other on the same plane asthe first installation electrode; 1-2) forming an insulating barriersurrounding an electrode line region in which a nano-scale LED device isable to be installed on the base substrate; and 1-3) injecting thesolution including a plurality of nano-scale LED devices into theelectrode line region surrounded by the insulating barrier.

First, the operation 1-1) may include manufacturing the electrode lineincluding the base substrate, the first installation electrode formed onthe base substrate, and the second installation electrode formed to bespaced apart from each other on the same plane as the first installationelectrode.

Next, the operation 1-2) may include forming the insulating barriersurrounding the electrode line region in which the nano-scale LED deviceis able to be installed on the base substrate.

The insulating barrier may perform a function of allowing the nano-scaleLED devices to be able to be arranged in the electrode line region to bedesired by preventing the solution including the nano-scale LED devicefrom being diffused outside the electrode line region in which thenano-scale LED device is installed when the solution including thenano-scale LED devices is injected into the electrode line in theoperation 1-3).

The insulating barrier may be manufactured through a manufacturingmethod which will be described hereinafter, but the manufacture methodof the insulating barrier is not limited thereto.

In detail, FIGS. 11A through 11F are diagrams illustrating amanufacturing process of forming a base substrate 100, and an insulatingbarrier 107 formed in an electrode line formed on the base substrate 100according to one implementation example of the present invention, andthe insulating barrier 107 may be manufactured after manufacturing theelectrode lines 103 a, 103 b deposited on the base substrate 100 likeFIG. 2f described above.

First, like FIG. 11A, an insulating layer 104 may be formed on the basesubstrate 100 and the electrode lines 103 a and 103 b formed on the basesubstrate 100. The insulating layer 104 may be a layer forming theinsulating barrier after performing a process which will be described,and a material of the insulating layer 104 may be an insulating materialwhich is generally used in the art, desirably any one or more amonginorganic insulating materials such as SiO₂, Si₃N₄, Al₂O₃, HfO₂, Y₂O₃,TiO₂, and various transparent polymer insulating materials. A method ofcoating the inorganic insulating material on the base substrate 100, andthe electrode lines 103 a and 103 b formed on the base substrate 100 maybe any one of chemical vapor deposition, atomic layer deposition, vacuumdeposition, e-beam deposition, and spin coating methods, desirable thechemical vapor deposition method, but is not limited thereto. Further, amethod of coating a polymer insulating layer may be any one of spincoating, spray coating, and screen printing methods, preferably, thespin coating method, but is not limited thereto, and a detailed coatingmethod may be performed by a well-known method in the art. A thicknessof the coated insulating layer 104 may be half of a radius of thenano-scale LED device so that the nano-scale LED device does not spillout and does not have an influence on a post process, and generally, bea thickness which is not able to have an influence on the pose process,preferably 0.1 to 100 μm, and more preferably 0.3 to 10 μm. When thethickness does not satisfy the range, there may be a problem in which itis difficult to manufacture a product including the nano-scale LEDelectrode assembly by having an influence on the post process, and whenthe thickness of the insulating layer is much smaller than a diameter ofthe nano-scale LED device, an effect of preventing spreadability of thenano-scale LED device through the insulating barrier may be decreased,and there may be a problem in which the solution including thenano-scale LED device spills over outside the insulating barrier.

After this, a photo resist (PR) 105 may be coated on the insulatinglayer 104. The photo resist may be a photo resist which is generallyused in the art. A method of coating the photo resist on the insulatinglayer 104 may be any one of spin coating, spray coating, and screenprinting methods, preferably, the spin coating method, but is notlimited thereto, and a detailed method may be a well-known method in theart. A thickness of the coated photo resist 105 may be greater than thatof the insulating layer coated by a mask used when etching, andaccordingly, be 1 to 20 μm. The thickness of the coated photo resist 105may be diversely changed according to a purpose later.

As described above, a mask 106 corresponding to a horizontalcross-sectional shape of the insulating barrier may be located on thephoto resist layer 105 like FIG. 11C after forming the photo resistlayer 105 on the insulating layer 104, and an ultraviolet ray may beexposed above the mask 106.

After this, a process of removing the exposed photo resist layer bysoaking the exposed photo resist layer in a conventional photo resistsolvent may be performed, and through this, the exposed photo resistlayer corresponding to the electrode line region in which the nano-scaleLED devices are installed like FIG. 11D may be removed.

Next, a process of removing the exposed insulating layer through theetching on a region of the insulating layer exposed by removing thephoto resist layer may be performed. The etching may be a wet etching ora dry etching, preferably the dry etching. A detailed method of theetching may be a well-known method in the art. In detail, the dryetching may be any one or more of a plasma etching, a sputter etching, areactive ion etching, and a reactive ion beam etching. However, adetailed etching method is not limited thereto. When removing theinsulating layer exposed through the etching, the base substrate 100 andthe electrode lines 103 a and 103 b may be exposed as shown in FIG. 11E.

Next, like FIG. 11F, when the photo resist layer 105 coated on the basesubstrate 100 is removed using any one photo resist remover amongacetone, 1-methyl-2-pyrrolidone (NMP), and dimethyl sulfoxide (DMSO), aninsulating barrier 104′ may be manufactured in a region excluding aregion (P of FIG. 11F) in which the nano-scale LED device issubstantially installed on the base substrate 100.

Next, the operation 1-3) may include injecting the solution includingthe plurality of nano-scale LED devices into the electrode line regionsurrounded by the insulating barrier.

In detail, FIGS. 12A through 12C are perspective view illustrating aprocess of manufacturing a nano-scale electrode assembly according toone implementation example of the present invention, and as shown inFIG. 12A, the solution 120 and 140 including the plurality of nano-scaleLED devices may be injected into the region of the electrode lines 110and 130 surrounded by the insulating barrier 150 formed on the basesubstrate 100. In this case, compared with the case of FIG. 10A, thesolution including the plurality of nano-scale LED devices may bedirectly positioned in a desired electrode line region. Further, theremay be an advantage of preventing the nano-scale LED devices from beinglocated in an electrode line region in which the nano-scale LED devicesdo not desire to be installed and/or a region in which the electrodelines are not present since the nano-scale LED devices spill overoutside the electrode line in the solution after injecting the solution.Meanwhile, since a description related to FIGS. 12B and 12C is the sameas that regarding FIGS. 10B and 10C in a description of the process (2)according to the present invention which will be described hereinafter,and a detailed description may be replaced by a content which will bedescribed hereinafter.

Next, the first implementation example of the present invention maycorrespond to the process (2), and the process (2) may include causingthe plurality of LED devices to self-align by applying the power to theelectrode line in order to simultaneously connect the plurality ofnano-scale LED devices to the first installation electrode and thesecond installation electrode as shown in FIG. 10B.

The plurality of nano-scale LED devices included in the nano-scale LEDelectrode assembly according to the present invention may beself-aligned by applying the power to the first installation electrodeand the second installation electrode, and be simultaneously connectedto the first installation electrode and the second installationelectrode as shown in FIG. 10C.

In this case, in order to remarkably increase the number of nano-scaleLED devices which are installed per a unit area by remarkably improvingthe alignment of the nano-scale LED devices which are installed by beingself-aligned on the electrode, the power may be alternating currentpower in which a voltage is 10 to 500 V_(pp), and a frequency is 50 kHzto 1 GHz, preferably, be the alternating current power having a sinewave, and more preferably, be the alternating current power having asine wave in which the voltage is 35 to 200V_(pp), and a frequency is 90kHz to 100 MHz.

When the voltage of the power is more than 500 V_(pp), the number ofnano-scale LED devices installed may be remarkably decreased, and theremay be a problem in which a short circuit is generated in the electrodeline when a high voltage has a great effect on the electrode, even whensatisfying the frequency range. When the voltage is less than 10V_(pp),a smaller number of nano-scale LED devices may be installed comparedwith the voltage is excessive by a low voltage even when satisfying thefrequency range, and also the alignment of the installed nano-scale LEDdevices may be remarkably decreased.

Further, even when satisfying the voltage range when the frequency isless than 50 kHz, the number of nano-scale LED devices installed may beremarkably decreased, and there may be a problem in which the polarizedlight is not emitted since the alignment between the devices is veryirregular. Moreover, when the frequency is more than 1 GHz, thealignment may be decreased since the nano-scale LED device does notadapt to the alternating current power which is quickly changed, andthere may be a problem in which the polarized light is not emitted likethe case in which the frequency is small.

In detail, in a condition such as a type, a voltage, and a frequency ofpower applying for the self alignment, the power may be power changedwith a amplitude and a period, and a waveform of the power may be apulse waveform configured as a sinusoidal wave such as a sine wave orpulse waveforms excluding the sinusoidal wave. Meanwhile, as theconventional power condition disclosed by the inventor of the presentinvention, a voltage (amplitude) of the power is 0.1 V to 1000V and thefrequency is 10 Hz to 100 GHz, but the inventor of the present inventionrecognizes that the alignment of the nano-scale devices is increased,that is, the longitudinal directions of the devices are substantiallyclose to parallel, and further, the longitudinal directions of thedevices are close to be perpendicular to the installation electrode whenhaving a specific wave, and specific voltage and frequency through acontinuous study for further improving the alignment between the devicesand the alignment with the installation electrode, the light having ahigh intensity is emitted as the longitudinal directions are close to beperpendicular to the installation electrode, and in this case, theemitted light is the polarized light, and on the contrary, the polarizedlight is not emitted even when the intensity of the emitted light issatisfied in some degree, or the polarized light is emitted but anentire intensity of the emitted light is decreased when the voltage isthe same but the frequency is changed.

In detail, FIG. 8C is a graph illustrating a relative intensity of lightpassing through a polarizer according to a polarizer rotation angle of anano-scale LED electrode assembly according to one implementationexample of the present invention, it may be confirmed that a material incharacteristic emitting the polarized light is excellent compared withthe nano-scale LED electrode assembly shown in FIG. 8C. since thepolarization ratio is calculated as 0.45 according to Equation 1described above in the graph shown in FIG. 8C, and the polarizationratio of the nano-scale LED electrode assembly according to FIG. 13C iscalculated 0.55 according to Equation 1 described above.

However, when considering the intensity of the light in which thenano-scale LED electrode assembly emits overall, the nano-scale LEDelectrode assembly shown in FIG. 8A emits much brighter light whencomparing FIGS. 8A and 13A, and it may be confirmed that the nano-scaleLED electrode assembly shown in FIG. 8B has a greater number ofnano-scale LED devices than the nano-scale LED electrode assembly shownin FIG. 13B through the optical microscope photographs shown in FIGS. 8Band 13B. Accordingly, even when the light having a desired level isemitted by the condition such as the voltage, the frequency, and thewaveform of the power applied when causing the devices to self-align inFIG. 13A, it may be confirmed that the polarized light is decreased orlight which is not the polarized light is emitted. Further, on thecontrary, since the alignment of the devices installed is excellent asthe number of devices is remarkably small, the light having the desiredlevel may not be emitted even when the polarized light is emitted.

Meanwhile, the method of manufacturing the nano-scale LED electrodeassembly according to one implementation example of the presentinvention may further include forming a metal ohmic layer in aconnection portion of the first installation electrode, the secondelectrode, and the nano-scale LED device, as a process (3) after theprocess (2).

The plurality of nano-scale LED devices may emit the light when applyingthe power to the two different electrodes to which the plurality ofnano-scale LED devices are connected, and in this case, a greatresistance between the nano-scale LED devices may be generated, and thusthe forming the metal ohmic layer may be further included in order toreduce the resistance.

The metal ohmic layer may be formed using any methods which are wellknown in the art, and the method of forming the metal ohmic layer is notlimited thereto, and a description thereof will be omitted.

The nano-cell LED electrode assemblies according to the first to thirdimplementation examples of the present invention described above may beapplied to the polarized LED lamp.

In detail, the polarized LED lamp may include a supporter, and thenano-scale LED electrode assembly according to the present inventionincluded inside the supporter.

In detail, FIG. 14 is a cross-sectional view of a polarized LED lampaccording to one implementation example of the present invention, atleast one of the nano-scale LED electrode assemblies 160 may be includedinside the supporter 155, and in this case, the nano-scale LED electrodeassembly 160 may be included inside the supporter 155 by locating thebase substrate 160 d therebetween. Further, a fluorescent substance 170may be included in a remaining space of the supporter 155.

Further, in detail, FIGS. 15 and 16 are perspective views of polarizedLED lamps according to implementation examples of the present invention,as shown in FIG. 15, a plurality of nano-scale LED electrode assemblies331, 332, and 333 may be arranged on the supporter 300 so as to have aline arrangement, and as shown in FIG. 16, the plurality of nano-scaleLED electrode assemblies 331, 332, and 333 may be arranged on thesupporter 300 having a plane shape so as to have a plane arrangement.

First, the supporter 155 will be described. The supporter which is ableto be used in the present invention may generally be any supporters usedfor the LED lamp without limitations, but preferably any one materialselected from groups consisting of organic resins, ceramics, metals, andinorganic resins, and the material may be transparent or opaque.Further, a shape of the supporter may be a cup shape or flat plateshape, but is not limited thereto, and be not specially limited sincethe shape of the supporter is diversely designed according to a purpose.

When the supporter 155 has the cup shape, an internal volume may bediversely changed in proportion to a size and a density of the electrodein which the nano-scale LED devices are arranged. Further, the internalvolume of the supporter may be changed according to a thickness of thesupporter. The thickness of the supporter may be the same at everyposition of the supporter or be different at some positions. Since thethickness of the supporter is diversely designed according to a purpose,it is not specially limited.

Next, the base substrate 160 d will be described. A material of the basesubstrate 160 d may be any one selected from groups consisting of glass,plastic, ceramic, and metal, but is not limited thereto. The basesubstrate 160 d may use the same material as the supporter 150, and thebase substrate and the supporter may use a one-piece material.Preferably, the base substrate may be transparent. Further, preferably,the base substrate may use a flexible material. A dimension of the basesubstrate in the nano-scale LED electrode assembly is not speciallylimited, and a size of the base substrate may be changed from microunits to meter units according to whether an application is a pointlight source or a surface light source. The thickness of the basesubstrate may be 10 μm to 1 mm, but is not limited thereto, and may bechanged according to the material and the internal volume of thesupporter 150 in which the base substrate 160 d is located, thearrangement of the electrodes formed on the base substrate or an area ofthe electrode region of the arranged electrode which will be describedhereinafter.

Further, preferably, the nano-scale LED electrode assembly according toone implementation example of the present invention may include one of anano-scale UV LED device, a nano-scale blue LED device, a nano-scalegreen LED device, a nano-scale yellow LED device, a nano-scale amber LEDdevice, and a nano-scale red LED device. Through this, oneimplementation example of the present invention may be an LED lamp inwhich any one among UV light, blue light, green light, yellow light,amber light, and red light is emitted.

Further, according to one implementation example of the presentinvention, a fluorescent substance included inside the supporter andexcited by the light emitted from the nano-scale LED devices may befurther included.

As an example, when the nano-scale LED device is the nano-scale UV LEDdevice, preferably, the fluorescent substance excited by the UV may be afluorescent substance which is any one among blue, yellow, green, amber,and red, and in this case, the nano-scale LED device may be a monochromeLED lamp emitting the selected any one color. Further, preferably, thefluorescent substance excited by the UV may be one or more among blue,yellow, green, amber, and red, more preferably a mixed fluorescentsubstance of any one type among blue/yellow, blue/green/red, andblue/green/amber/red, and in this case, white light may be emitted bythe fluorescent substance.

A detailed type of the fluorescent substance which is able to be mixedmay be changed according to a color emitted from the nano-scale LEDdevice, and since the mixture may be a well-known mixture, and thefluorescent substance is not specially limited in the present invention.

As an example, when the nano-scale LED device is the nano-scale blue LEDdevice, preferably, the fluorescent substance excited by blue may be afluorescent substance which is any one or more among yellow, green,amber, and red. More preferably, when the fluorescent substance may be amixed fluorescent substance of any one type of mixed fluorescentsubstances such as blue/yellow, blue/green/red, andblue/green/amber/red, and in this case, white light may be emitted bythe fluorescent substance. Preferably, the yellow fluorescent substancemay be any one or more selected from groups consisting of Y₃Al₅O₁₂:Eu,Lu₃Al₅O₁₂:Eu, (Sr,Ba)₃SiO₅:Eu, (Sr,Ba,Ca)₂SiO₄:Eu, Ca-α-SiAlON:Eu, and(Ba,Eu)ZrSi₃O₉. Preferably, the blue fluorescent substance may be anyone or more selected from groups consisting of ZnS:AgCl, ZnS:AgAl,(Sr,Ba,Ca,Mg)₁₀(PO₄)₆Cl₂:Eu, (Ba,Sr)MgAl₁₀O₁₇:Eu, BaMgAl₁₀O₁₇:Eu,(Sr,Ba)₃MgSi₂O₈:Eu, LaSi₃N:Ce, LaSi₅Al₂ON₉:Eu, Sr₂MgSi₂O₇:Eu,CaMgSi₂O₆:Eu. Preferably, the green fluorescent substance may be any oneor more selected from groups consisting of SrGa₂S₄:Eu, (Sr,Ca)₃SiO₅:Eu,(Sr,Ba,Ca)SiO₄:Eu, Li₂SrSiO₄:Eu, Sr₃SiO₄:Ce,Li, β-SiALON:Eu, CaSc₂O₄:Ce,Ca₃Sc₂Si₃O₁₂:Ce, Ca-α-SiALON:Yb, Ca-α-SiALON:Eu, Li-α-SiALON:Eu,Ta₃Al₅O₁₂:Ce, Sr₂Si₅N₈:Ce, (Ca,Sr,Ba)Si₂O₂N₂:Eu, Ba₃Si₆O₁₂N₂:Eu,γ-AlON:Mn, and γ-AlON:Mn,Mg. Preferably, the amber fluorescent substancemay be any one or more selected from groups consisting of(Sr,Ba,Ca)₂SiO₄:Eu (Sr,Ba,Ca)₃SiO₅:Eu, and (Ca,Sr,Ba)₂Si₅N₈:Eu.Preferably, the red fluorescent substance may be any one or moreselected from groups consisting of (Sr,Ca)AlSiN₃:Eu, CaAlSiN₃:Eu,(Sr,Ca)S:Eu, CaSiN₂:Ce, SrSiN₂:Eu, Ba₂Si₅N₈:Eu, CaS:Eu, CaS:Eu,Ce,SrS:Eu, SrS:Eu,Ce, and Sr₂Si₅N₈:Eu. The detailed type of the fluorescentsubstance for each color described above is not limited thereto in thepresent invention.

Further, when the fluorescent substance is not included, the inside ofthe supporter may be filled with any one or more materials amongtransparent silicon binder, organic polymer, inorganic polymer, a glassmaterial, but the materials are not limited thereto.

According to one implementation example of the present invention, theplurality of nano-scale LED electrode assemblies may be included in theinside of the supporter.

Preferably, the plurality of nano-scale LED electrode assemblies may bearranged to have the line arrangement or the plane arrangement. However,the arrangement of the plurality of nano-scale LED assemblies is notlimited thereto, and a shape of the detailed arrangement of theplurality of nano-scale LED assemblies may be changed according to ashape of the supporter and/or a use purpose of the LED lamp in which thenano-scale electrode assembly is included.

Each of the plurality of nano-scale LED electrode assemblies mayindependently include any one among a nano-scale UV LED device, anano-scale blue LED device, a nano-scale green LED device, a nano-scaleyellow LED device, a nano-scale amber LED device, and a nano-scale redLED device. Accordingly, various colors may be emitted by including twoor more nano-scale electrode assemblies among a nano-scale blue LEDelectrode assembly, a nano-scale green LED electrode assembly, anano-scale red LED electrode assembly, a nano-scale amber LED electrodeassembly, and a nano-scale yellow LED electrode assembly therebypolarized LED lamp emitting polarized light may be implemented. Further,the white polarized LED lamp may be implemented by including a pluralityof the nano-scale blue LED electrode assembly, the nano-scale green LEDelectrode assembly, and the nano-scale red LED electrode assembly.

As a detailed implementation example capable of implementing the whitepolarized LED lamp, the white polarized LED lamp may be implemented byincluding a transparent resin layer from which the fluorescent substanceis removed in the supporter by configuring using the nano-scale blue LEDelectrode assembly, the nano-scale green LED electrode assembly, thenano-scale red LED electrode assembly, by including the nano-scale blueLED electrode assembly, and any one or more among yellow, green, amber,and red fluorescent substances as the fluorescent substance excited byblue in the supporter, or by including the nano-scale UV LED electrodeassembly, and any one or more among yellow, green, amber, and redfluorescent substances as the fluorescent substance excited by the UV inthe supporter.

The first to third implementation examples of the present invention andan application example including the examples were describedhereinbefore. However, the first to third implementation examples aremerely implementation examples capable of being implemented by atechnical spirit of the present invention, and unequal relations betweenthe examples are not present. The present invention will be described inmore detail with reference to embodiments which will be describedhereinafter, but the embodiments do not limit the scope of the presentinvention, and should be interpreted as helping the understanding of thepresent invention.

Embodiment 1

The electrode line shown in FIG. 1 is manufactured on the base substratehaving a thickness of 800 μm of a quartz material. In this case, in theelectrode line, a width of the first installation electrode is 3 μm, awidth of the second installation electrode is 3 μm, an interval betweenthe first installation electrode and the second installation electrodewhich are adjacent to each other is 2.2 μm, and a thickness of theelectrode is 0.2 μm, a material of the first installation electrode andthe second installation electrode may be gold, and an area of a regionof the electrode line in which the nano-scale LED device is installed is4.2×10⁷ μm². After this, the insulating barrier shown in FIGS. 11Athrough 11F is formed on the base substrate, a material of theinsulating barrier is silicon dioxide, a height which is from the basesubstrate to an end of the insulating barrier is 0.1 μm, and theinsulating barrier is formed on the base substrate by excluding theregion of the electrode line in which the nano-scale LED device isinstalled (4.2×10⁷ μm²).

After this, 0.7 parts by weight of nano-scale LED devices, withspecifications listed in the following Table 1 and having a structure asshown in FIG. 5 and in which a portion of an active layer of each of thenano-scale LED devices was coated with an insulating coating film aslisted in the following Table 1, was mixed with 100 parts by weight ofacetone to prepare a dispersion solution including the nano-scale LEDdevices.

After this, the nano-scale LED device is self-aligned by applying thealternating current power of a sine wave having a voltage of 50Vpp and afrequency of 950 kHz to the electrode line and dropping the solution of9 μl eight times. After this, in order to improve contact between thenano-scale LED device and the electrode line, a thermal process isperformed during two minutes at a temperature of 810° C., in a pressureof nitrogen atmosphere 5.0×10⁻¹ torr using a rapid thermal annealing(RTA), and next, an electroless deposition using gold solution of 0.05mM and a copper metal foil may be repeatedly performed during every tenminute and two times at a room temperature. The RTA may be againperformed on a gold nanoparticle attached between the electrode line andthe nano-scale LED device using the electroless deposition, and thenano-scale LED electrode assembly having a specification shown in thefollowing Table 1 may be manufactured by improving the electricalcontact.

TABLE 1 Material Length(μm) Diameter(μm) First electrode layer Chrome0.03 0.5 First conductive n-GaN 2.14 0.5 semiconductor layer Activelayer InGaN 0.1 0.5 Second conducive p-GaN 0.2 0.5 semiconductor layerSecond electrode Chrome 0.03 0.5 layer Insulating film Aluminum oxideThickness 0.02 Nano-scale LED — 2.5 0.52 device

Embodiments 2 to 4

Embodiments 2 to 4 may be manufactured like embodiment 1, but thenano-scale LED electrode assembly having a specification shown in thefollowing Table 2 may be manufactured by changing the voltage and thefrequency of the power applied to the electrode line as shown in Table2.

Comparison Example 1

The nano-scale LED electrode assembly may be manufactured likeEmbodiment 1, the nano-scale LED electrode assembly having thespecification shown in the following Table 2 be manufactured by changingthe voltage and the frequency of the power applied to the electrodeline.

Experiment Example

The following material properties regarding the nano-scale LED electrodeassembly manufactured through the embodiment and the comparison exampleare measured.

1. Measurement of Installation Angle of Nano-Scale LED Device

The total number of LED devices emitting by inspecting an angle betweenthe nano-scale LED devices emitting after applying the driving power tothe nano-scale LED device electrode assembly and the installationelectrode using an optical microscope, and the installation angle ofeach of the devices according to a definition of the present inventionare measured, and average installation angle which is calculated asshown in Table 2. In this case, measurement results regardingEmbodiments 1, 2, 4, and 5 are shown in FIGS. 17 to 20, respectively.

2. Measurement of Polarizer Degree

Results obtained by locating the polarizer (SM, DEBF-D400-DS) on anupper surface of a light emitting surface of the nano-scale LEDelectrode assembly, and measuring the polarized light passing throughthe polarizer by a charge coupled device (CCD, PSI Co. Ltd.) in thestraight direction while rotating the polarizer within −90°˜+90° afterapplying the alternating current power of a sine wave having a voltageof 60Vpp and a frequency of 60 Hz in order to drive the nano-scale LEDelectrode assembly are shown in Table 2, FIG. 6C (Embodiment 1), FIG. 7C(Embodiment 2), FIG. 8C (Embodiment 4), and FIG. 13C (Embodiment 5).

As being confirmed through each drawing, it may be known that, when anangle formed by the nano-scale LED device and a polarization axis of thepolarizer is close to 0°, the intensity of the emitted light is great,and when the angle is changed from 0° to ±90°, the intensity of theemitted light is small. However, according to each of the implementationexamples, a polarizer degree of the light is different, and according toresults obtained by calculating using Equation 1, since the polarizationratio of the nano-scale LED electrode assembly according to FIG. 6C is0.61, the polarization ratio of the nano-scale LED electrode assemblyaccording to FIG. 7C is 0.60, the polarization ratio of the nano-scaleLED electrode assembly according to FIG. 8C is 0.45, and thepolarization ratio of the nano-scale LED electrode assembly according toFIG. 13C is 0.55, it may be known that the excellent polarized light isemitted.

3. Photography of Optical Microscope of Nano-Scale LED ElectrodeAssembly

Photographs obtained by capturing the nano-scale LED electrodeassemblies using the optical microscope are shown in FIG. 6B (Embodiment1), FIG. 7B (Embodiment 2), FIG. 8B (Embodiment 4), and FIG. 13B(Embodiment 5).

The alignment of the nano-scale LED devices installed on the electrodethrough the photographs captured by the optical microscope, and thenumber of nano-scale LED devices per a unit electrode area may beevaluated with the naked eye.

In detail, the number of nano-scale LED devices installed per the unitelectrode area may be remarkably increased as going from the nano-scaleLED electrode assembly shown in FIG. 8B in which the polarization ratioof the emitted light is increased to the nano-scale LED electrodeassemblies shown in FIG. 7B and FIG. 6B. Through this, a greater numberof electrodes may be installed in the electrode compared with when beinginstalled in the electrode as the alignment of the nano-scale LEDdevices is increased.

Meanwhile, it may be confirmed that the nano-scale LED electrodeassembly according to FIG. 13B has a greater polarization ratio than thenano-scale LED electrode assembly according to FIG. 8B, but thenano-scale LED electrode assembly according to FIG. 8B has a greaternumber of emitted nano-scale LED devices than the nano-scale LEDelectrode assembly according to FIG. 13B. Accordingly, it may beconfirmed that, even when the number of nano-scale LED devices installedis increased according to the condition such as the voltage, thefrequency, and the waveform of the power, the polarized light isdecreased or light which is not the polarized light is emitted.

4. Visual Evaluation of Light Emitting Intensity

A portion of a photograph obtained by capturing the nano-scale LEDelectrode assembly in a darkroom after applying the alternating currentpower of a sine wave having a voltage of 60Vpp and a frequency of 60 Hzin order to drive the nano-scale LED electrode assembly is illustratedin each of FIGS. 6A (Embodiment 1), 7A (Embodiment 2), 8A (Embodiment4), and 13A (Embodiment 5).

In detail, it may be confirmed that the nano-scale LED electrodeassembly according to the implementation example of FIG. 6A isremarkably excellent in the intensity of emitted light compared with thenano-scale LED electrode assemblies according to the implementationexamples of FIGS. 7A and 13A. Meanwhile, it may be known that thenano-scale LED electrode assembly of FIG. 8A is brighter than that ofFIG. 13A, in a light emitting degree.

TABLE 2 Embodiment Embodiment Embodiment Embodiment EmbodimentComparison 1 2 3 4 5 Example1 Nano- Power applying for Vpp 50 V, Vpp 60V, Vpp 40 V, Vpp 50 V, Vpp 15 V, Vpp 50 V, scale self alignment 950 kHz950 kHz 950 kHz 100 kHz 950 kHz 30 kHz LED The number of all 8602 63165245 3970 1993 2986 Electrode of nano-scale LED Assembly devicesemitting light Average 4.74 8.21 3.62 6.07 3.20 33.18 installation angle(°) A¹⁾(number %²⁾) 8569 (99.6) 6231 (98.6) 5155 (98.3) 3830 (96.5) 1954(98.1) 2215 (74.2) B³⁾(number %²⁾) 8200 (95.3) 5676 (89.9) 4595 (87.6)3269 (82.4) 1736 (87.1) 394 (13.2) C⁴⁾(number %²⁾) 7598 (88.3) 5121(81.1) 4374 (83.4) 2849 (71.8) 1607 (80.6) 262 (8.8) Polarizer degree0.61 0.60 0.55 0.45 0.55 0.22 ¹⁾A: a device having an angle which iswithin a range of an average installation angle ± 30° as an installationangle ²⁾number % based on all of emitting nano-scale LED devices ³⁾B: adevice having an angle which is within a range of an averageinstallation angle ± 20° as an installation angle ⁴⁾C: a device havingan angle which is within a range of an average installation angle ± 10°as an installation angle

In detail, as being confirmed from Table 2, in the comparison example 1in which the frequency of the power applied when installing thenano-scale LED devices on the installation electrode is small, thealignment of the devices is not remarkably good since a turning force ofthe device by an electric field is small, and thus the partiallypolarized light in which the polarization ratio is 0.22 is emitted.

On the contrary, in the embodiments, it may be confirmed that thepartially polarized light in which the polarization ratio is 0.45 ormore is emitted since the alignment of the devices is remarkablyexcellent.

Meanwhile, it may be confirmed that the number of nano-scale LED deviceswhich is actually installed and emitted is different since a forcecapable of installing by moving the device is great as the appliedvoltage is increased through the comparison of embodiment 4, embodiment5, and comparison example 1. Further, it may be confirmed that thealignment of the devices is remarkably influenced since the turningforces of the devices are different according to the frequency of theapplied power.

The nano-scale LED electrode assembly according to the implementationexample of the present invention may emit the partially polarized lightclose to the linearly polarized light as the emitted light by remarkablyimproving the alignment of the nano-scale LED devices installed on thenano-scale electrode line. Further, the number of nano-scale LED devicesinstalled may be remarkably increased, and the number of LED devicesinstalled per the unit area of the installation electrode may beincreased. Moreover, the intensity of the emitted light may be furtherimproved since the installed nano-scale LED devices are connected to thenano-scale electrode without defects such as the electrical shortcircuit, etc. Moreover, a remarkably excellent polarized light may beemitted without the polarizer transmitting only the polarized light in aspecific direction, and thus the nano-scale LED electrode assemblyaccording to the implementation example of the present invention may bewidely used in various fields requiring the polarized light such as thepolarized LED lamp, a backlight unit for display, etc.

What is claimed is:
 1. A nano-scale LED electrode assembly emittingpolarized light comprising an electrode line including a firstinstallation electrode and a second installation electrode which arespaced apart from each other on the same plane, and a plurality ofnano-scale light emitting diode (LED) devices in which one end in alongitudinal direction of a device is in contact with the firstinstallation electrode and the other end is in contact with the secondinstallation electrode, wherein the number of nano-scale LED deviceshaving an installation angle which is within an angle change range of±30° from an average installation angle of all of the nano-scale LEDdevices emitting light in the nano-scale LED electrode assembly is equalto or more than 80% of the total number of nano-scale LED devicesemitting light, and the installation angle is an acute angle amongangles formed by the nano-scale LED device and the first installationelectrode or the second installation electrode measured when theinstallation angle of a case in which the nano-scale LED device isinstalled to be perpendicular to the first installation electrode or thesecond installation electrode is defined as 0°.
 2. The nano-scale LEDelectrode assembly emitting the polarized light of claim 1, wherein thenano-scale LED device comprises a first conductive semiconductor layer,an active layer formed on the first conductive semiconductor layer, anda second conductive semiconductor layer formed on the active layer, andcomprises an insulating film covering an entire outer surface of atleast the active layer in order to prevent an electrical short circuitgenerated by contact between the active layer of the nano-scale LEDdevice and the electrode line.
 3. The nano-scale LED electrode assemblyemitting the polarized light of claim 1, wherein an aspect ratio of thenano-scale LED device is 1.2 to
 100. 4. The nano-scale LED electrodeassembly emitting the polarized light of claim 1, wherein the number ofnano-scale LED devices having an installation angle which is within theangle change range of ±30° based on the average installation angle asthe installation angle is equal to or more than 90% of the total numberof nano-scale LED devices emitting light.
 5. The nano-scale LEDelectrode assembly emitting the polarized light of claim 1, wherein thenumber of nano-scale LED devices having an installation angle which iswithin the angle change range of ±10° of the average installation angleof all of the nano-scale LED devices emitting light in the nano-scaleLED electrode assembly is equal to or more than 70% of the total numberof nano-scale LED devices emitting light.
 6. A nano-scale LED electrodeassembly emitting polarized light comprising an electrode line includinga first installation electrode and a second installation electrode whichare spaced apart from each other on the same plane, and a plurality ofnano-scale LED devices of which one end of the device in a longitudinaldirection is in contact with the first installation electrode and theother end is in contact with the second installation electrode, whereinthe nano-scale LED electrode assembly emits polarized light in which apolarization ratio according to the following Equation 1 is equal to ormore than 0.25, $\begin{matrix}{\rho = \frac{I_{\max} - I_{\min}}{I_{\max} + I_{\min}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$ in Equation 1, I_(max), and I_(min) are a maximumintensity and a minimum intensity of the light measured while rotating apolarization axis of a polarizer from −90° to +90° after placing thepolarizer on a light emitting surface of the nano-scale LED electrodeassembly.
 7. The nano-scale LED electrode assembly emitting thepolarized light of claim 6, wherein a polarization ratio according tothe Equation 1 is equal to or more than 0.40.
 8. A nano-scale LEDelectrode assembly emitting polarized light including an electrode lineincluding a first installation electrode and a second installationelectrode which are spaced apart from each other on the same plane, anda plurality of nano-scale LED devices of which one end of the device ina longitudinal direction is in contact with the first installationelectrode and the other end is in contact with the second installationelectrode, wherein an average installation angle of all of nano-scaleLED devices emitting in the nano-scale LED electrode assembly is equalto or less than 30°, and the installation angle is an acute angle amongangles formed by the nano-scale LED device and the first installationelectrode or the second installation electrode measured when theinstallation angle of a case in which the nano-scale LED device isinstalled to be perpendicular to the first installation electrode or thesecond installation electrode is defined as 0°.
 9. The nano-scale LEDelectrode assembly emitting the polarized light of claim 8, wherein theaverage installation angle is equal to or less than 20°.
 10. A polarizedlight emitting diode (LED) lamp, comprising: a supporter; and anano-scale LED electrode assembly according to claim 1 included insidethe supporter.
 11. The polarized LED lamp of claim 10, wherein thenano-scale LED electrode assembly includes one among a nano-scale UV LEDdevice, a nano-scale blue LED device, a nano-scale green LED device, anano-scale yellow LED device, a nano-scale amber LED device, and anano-scale red LED device.
 12. The polarized LED lamp of claim 10,wherein the supporter has a cup shape, and further comprises afluorescent substance included in a cup and excited by light emittedfrom a nano-scale LED electrode assembly.
 13. The polarized LED lamp ofclaim 10, wherein the lamp includes a plurality of nano-scale LEDelectrode assemblies, and each of the plurality of nano-scale LEDelectrode assemblies independently includes one among the nano-scale UVLED device, the nano-scale blue LED device, the nano-scale green LEDdevice, the nano-scale yellow LED device, the nano-scale amber LEDdevice, and the nano-scale red LED device.
 14. The polarized LED lamp ofclaim 13, wherein the plurality of nano-scale LED electrode assembliesare arranged to have a line arrangement or a plane arrangement.
 15. Thepolarized LED lamp of claim 12, wherein, when the nano-scale LEDelectrode assembly includes the nano-scale UV LED device, thefluorescent substance is one among blue, yellow, green, amber, and red,and when the nano-scale LED electrode assembly includes the nano-scaleblue LED device, the fluorescent substance is one among yellow, green,amber, and red.
 16. The polarized LED lamp of claim 13, wherein thepolarized LED lamp emits white light.